Perhaps you should try some spelling variations:
"modified notion approximation algorithms" » "modified network approximation algorithms", "modified time approximation algorithms", "modified one approximation algorithms"
"modified machine scheduling algorithm" » "modified machine annealing algorithm", "modified caging scheduling algorithm", "modified male scheduling algorithm", "modified passive scheduling algorithm"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified notion approximation algorithms") OR ("modified machine scheduling algorithm"))~.
• Removing quotes may allow a broader search: (( modified notion approximation algorithms ) or ( modified machine scheduling algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified notion approximation algorithms") or ("modified machine scheduling algorithm"))*.